Modern spacecraft include subsystems that take up minimal space when stored and then can be easily deployed into an operational configuration when the spacecraft achieves orbit or otherwise escapes the earth's atmosphere. Examples of such a subsystem include an antenna, solar power array, radiator, communications reflector, radar aperture, sun shade and solar sail. In addition to the aforementioned prerequisites of easy deployment and small size when in its stored or collapsed configuration, such a subsystem must have an efficient mass and deploy into the desired shape with high reliability.
A wide variety of large deployable structures have been used on spacecraft in conjunction with the aforementioned subsystems. In the late 1970's and 1980's, the wrap-rib antenna disclosed by Wada, B. K., Freeland, R. E., and Woods, A. A., “Development of the Structural Technology of a Large Deployable Antenna,” Proceedings of the 13th International Symposium of Space Technology and Science, Tokyo, Japan, pp. 395-400 (Jun. 28-Jul. 3, 1982), utilized deployable ribs to support a large mesh antenna. Other lightweight deployable structures suited for spacecraft include the flexible solar array disclosed by Olsen, M, “Flexible Solar-Array Mechanism,” Proceedings of the 7th Aerospace Mechanisms Symposium, NASA TMX-58103, pp. 233-249 (September 1972), and flown in 1971; and the L'Garde inflatable decoys from the 1970's and 1980's and the L'Garde inflatable antenna experiment in the 1990's, disclosed by Cheielewski, A., “Overview of Gossamer Structures,” Gossamer Spacecraft: Membrane Inflatable Structures Technology for Space Applications, Edited by C. H. M. Jenkins, Vol. 191, Progress in Astronautics and Aeronautics, AIAA, Virginia, pp. 1-33 (2001). Some of the most reliable have been tubular booms and coilable masts, such as those shown by Pelligrino, S., “Large Retractable Appendages in Spacecraft,” Journal of Spacecraft and Rockets, Vol. 32, No. 6 (November-December 1995).
Due to their relatively large dimensions and structural requirements, solar sails comprise an exclusive class of deployable space structures. Typical solar sail structures rely on tension-only members in order to minimize their mass, for example, suspending a highly flexible membrane film between cables as disclosed by Murphy, D., “Validation of a Scalable Solar Sailcraft System,” Journal of Spacecraft and Rockets, Vol. 44, No. 4 (July-August 2007); Leipold, M., et al., “ODISSEE—A Proposal for Demonstration of a Solar Sail in Earth Orbit,” Proceedings of the European Conference on Spacecraft Structures, Materials and Mechanical Testing, Braunschweig, Germany, 245-254 (Nov. 4-6, 1998); and Lichodziejewski D., et al., “Bringing an Effective Solar Sail Design Toward TRL 6,” Proceedings of the 39th AIAA Jet Propulsion Conference and Exhibit, MAA 2003-4659, Huntsville, Ala. (Jul. 20-23, 2003). Each of the aforementioned designs has successfully deployed a membrane film into the desired final configuration.
The advantage of the present invention is its enhanced reliability to achieve the final, deployed configuration. This reliability is attributed to the absence of kinematic joints and the continual application of tensile forces throughout the structure during deployment.